CS212001B1 - Method of electrolytic precipitation of the nickle and alloying elements alloys layers - Google Patents

Abstract

A process of electrolytic deposition of layers of nickel alloys, especially nickel alloyed with molybdenum, with tungsten, and with phosphorus, from an electrolyte on the basis of sulphosalicylate. The object to be coated is degreased, rinsed with activation solution, for example with sulphosalicylic acid, is electrolytically activated with nickel (II) chloride solution, and coated in an electrolyte containing compounds of alloying elements, a halide, wetting agents, and a luster-forming admixture.

Description

The invention relates to a method of electrolytic deposition. of nickel alloy layers with alloying elements, in particular molybdenum, tungsten and phosphorus, improving the alloys. by electrolytically secreted properties. thin. ’To. fat. layers. So far, nickel alloy layers with alloying elements, such as molybdenum, tungsten, have not been able to precipitate. Alloy layers of nickel with others. the elements are separated from weakly acid sulphate - based electrolytes or from alkaline electrolytic baths containing. ammonia and organic hydroxy acids. The deposited layers of these alloys are characterized by a high stress value, thereby becoming brittle and their adhesion to the base material is insufficient. From the above. the reason is their use for practice. problematic.

These drawbacks are overcome by the method of electrolytic deposition of nickel alloy layers with alloying elements, in particular molybdenum, tungsten and phosphorus according to the present invention, carried out from an electrolyte on a sulfosalicylan base. The subject matter of the invention is that after the degreasing, the metalized article is rinsed with an activating solution, e.g. sulfosalicylic acid, and then electrolytically activated, e.g. After rinsing the subject plated in an electrolyte which contains salts or other compounds of alloying elements in the range of from 0.001 to 0.25 moles of ³ 10 * ^1, and optionally the halide in the range from 0.01 to 0.2 and 10 ³ mol.m'1 innogenous and / or noninogenic surfactants such as sodium lauryl sulphate at a concentration of 0.002 to 0.04 10 ³ mol.m ^-1 and brighteners. . an additive such as saccharin,. coumarin at a concentration of from 0.01 to. 2.0 g / l.

The method according to the invention can:. cover common technical materials, eg steel, copper alloys, nickel. On. metal-plated objects can be created. thin to. Thick layers of. alloy materials in a thickness ranging from 0.5 µm. to. a few millimeters. The deposited layers are characterized by good adhesion and mechanical properties, their microhardness ranges from 300 to 800. HM at the same time a low macro-tension level of 50 to 150 MPa. Said alloys can be used as functional galvanic layers on highly stressed machine parts exposed to adhesive wear. Alloys are also good. corrosion resistance.

The process according to the invention is illustrated by examples, which do not limit its scope.

Example 1 \

Electric motor shaft with minus tolerance

0.06 mm was rinsed in 0% sulfosalicylic acid after degreasing. It was then activated. at 25 ° C. and then cathodically activated in a nickel chloride solution of. pH = 2. The plating was performed in an electrolyte containing 75 10 ³ mol.m -1. sulfosalicylan. of nickel, 0.005 10 ³ mol. m ^_ 1. .sodného molybdate, 0.04 ³ 10 mol m ^_ 1 nickel bromide and 1.2 g / 1 of saccharin. The alloy metal layer deposited at an average current density of 7 A / dm ² contained 2.4%. molybdenum. Its microhardness was 490 HM.

Example 2

The brake cylinder was after degreasing. rinsed in 5% fluoroboric acid at 20 ° C. It was then electrolytically activated in. nickel chloride solution having a pH value of 2.5. Exclusion of nickel-tungsten alloy layer. took place. in the electrolyte. having a composition of 0.70 103 mol.m -1. nickel sulfosalicylan,. 0.05 103 mol / ml. iodide. of potassium boric acid, 0.3 103 mol. m'1 of sodium tungsten. At a cathodic current density of 2.5 A / dm ^{< 2 >} a 15 [mu] m layer containing 3.1% tungsten was deposited. Its microhardness was 730 HM.

Example 3

The steel sheet was rinsed after degreasing. in 8% sulfosalicylic acid. It was then activated at 25 ° C and cathodically activated in a nickel chloride solution of ρΗ = 2. The actual plating was carried out in an electrolyte containing 0.8 10 ³ mol.m -1 nickel sulphosalicylate, 0.05 10 ³ mol.m -1 acid. phosphorous .mol ⁴ 0.05 103 potassium bromide. . 0.8 g / l saccharin, 0.1 g / l coumarin. and 0.5 µg / L dipropylnaphthalenesulfonic acid. A layer having a thickness of 30 µm was deposited in this way. Its microhardness, which was 738 HM, increased after thermal exposure to 450 ° C. to 1020 HM.

Example 4

Bearing ring - o minus. a tolerance of 0.1 mm was degreased and after rinsing in 10% sulfosalicylic acid activated at 20 ° C. . It was then cathodically activated in solution. nickel chloride o. pH = 2.5, and then metallized in an electrolyte containing 0.71 103 mol.m -1 nickel sulfosalicylanate, 0.10 103 mol.m -1 ferrous sulfosalicylate, 0.05 103 molM ^-1 potassium bromide, and 0. 2 g / l of sodium laurilsulphate.

At an average cathodic density of 6 A / d‘2, a 0.2 mm thick nickel-iron alloy layer containing 14.1% iron was deposited. Mon. regrind on. required dimension. the bearing ring was used for its function.

Claims (1)

OBJECT OF THE INVENTION Process for the electrolytic deposition of nickel alloy layers with alloying elements, in particular molybdenum, tungsten and phosphorus from - electrolyte. sulfosalicylan base, characterized in that, after degreasing, the metallized article is rinsed with an activating solution, such as sulfosalicylic acid, and then electrolytically activated, e.g. compounds of alloying elements in the range from 0.001 to 0.25 1 ^ 0 ^ ³ mol.n ^'1 and, where appropriate halide in the range from 0.01 to 0.2 10 ^{3 1} mol.im ionnogenní and / or nonionic surfactant. e.g. - laurilsíran sodium - a concentration from 0.002 to 0.04 - 103 m _A i _m i, and brighteners, e.g. saccharin, coumarin at a concentration of 0.01 - 2.0 g / 1st